Monotheism and Polytheism

Monotheists believe in one God. Most Christians, despite various problems with the Trinity, say they believe that there is exactly one God. But why do they say this? The main arguments for the existence of God are all compatible with the existence of many Gods. They are all compatible with polytheism. Consider briefly (1) the design argument; (2) the cosmological argument; and (3) the ontological argument.

The Design Argument. The design argument reasons from the orderliness of our universe to the existence of some designer. The design argument is consistent with the thesis that our universe has a plurality of divine designers. Hume says “A great number of men join in building a house or ship, in rearing a city, in framing a commonwealth: Why may not several deities combine in framing a world?” (1779: 77) So the design argument is consistent with the existence of many Gods.

The Cosmological Argument. The cosmological argument reasons from causal or explanatory sequences in our universe to the existence of a First Cause or First Explainer (or something similar). The cosmological argument is consistent with the thesis that our universe has a plurality of first causes or necessary grounds (Bartel, 1982). And it’s consistent with the notion that other possible universes all have their own First Causes. Here’s how Bartel puts it:

It seems rather rash to affirm without further ado that there must exist one and only one uncaused First Cause. Might there not be several causally-independent beings who are collectively responsible for the existence of all contingent beings? Or, granted that there exists only one First Cause in the actual world, might there not exist two or more First Causes in some other possible world? Or, granted that there cannot be more than one First Cause in each possible world, might not the First Cause in one possible world be distinct from the First Cause in another possible world? (Bartel, 1982: 34)

So the cosmological argument is consistent with the existence of many Gods.

The Ontological Argument. The ontological argument goes roughly like this: (1) God is that than which no greater is possible; (2) if God doesn’t exist, then any existing thing is greater than God; (3) but that contradicts the definition of God; (4) therefore, God exists. If this argument works for God, then it works for another God, call it God-2, who is also that than which no greater is possible. And it works for God-3, God-4, and so on. The ontological argument is consistent with the existence of an infinity of maximally perfect beings (e.g. Grim, 1982; Kane, 1984; Leftow, 1988; Harwood, 1999).

So why do monotheists say there is one God? What’s the argument? If you believe in the traditional arguments for God, then why not accept polytheism?

Swinburne says “Theism is simpler than polytheism” (2010: 40). But why is it simpler? Swinburne seems to think that positing one infinite God is simpler than positing many finite Gods. And that’s just false. One infinitely complex thing is equivalent in its complexity to infinitely many finitely complex things. Positing the one infinite number Aleph-0 is equivalent to positing the entire infinite sequence of finite natural numbers.

I’m not aware of a single philosophical argument for monotheism. Surely this is just a failure of my awareness. But I’ve actually been looking (through academic resources like The Philosophers Index, JSTOR, Google Scholar, and so on). Not one article shows up that aims to defend the uniqueness of God. I’m guessing that there aren’t any good arguments for the uniqueness of God. So here’s a nice closing quote:

Polytheists, who are unduly despised, accept the idea of higher or greater and lower or lesser forms of being. But they often regard the higher forms as coming later, with their arrival marked by the increasing progress and differentiation of the universe, symbolized by the successive generations of the gods. They might well say that the idea of a hierarchy of greatness makes much more sense if we introduce lesser gods from whom the greater can gradually emerge without the inelegant monotheists’ leap straight from humanity to the Most High God. (Hughes, 1990: 349)

It makes far more sense to posit an endless series of ever-greater gods. If you don’t want lots of gods in our universe, just go modal: every possible universe gets exactly one god, its own local deity. Here it’s also interesting to note that many atheistic objections to the existence of God don’t apply to the existence of the finite gods of modal polytheism.

Bartel, T. (1982) Cosmological arguments and the uniqueness of God. International Journal for Philosophy of Religion 13 (1), 23-31.

Grim, P. (1982) In behalf of ‘In behalf of the fool’. International Journal for the Philosophy of Religion 13, 33-42.